Furnace.



Patented Mar. 23, 1915.

BSHEETSWSHEBT 1.

G. FURUHOLMEN.

PURNACE.

APPLICATION MLM) JAN. 9. 101s,

Ur. FURUHOLMEN.

FURNACE.

APPLNANO Patented Mar. 23, 1816.

3 SEEETSSHEBT 2 Zzwesses @n L@ N 7d G. FURUHLMEN.

PURNACE.

APPLICATION FILED JAN. 9. w13.

1 ',1 82,573. Patented Mar. 23, 1915.

3 SHEETS'SHEETS.

LMJ

UNITED STATES .3ATENT OFFICE.

GEORGE FURUHOLMN. Of MNNEAPOLTS. MINNESOTA.

FURNACE.

Appiicaticn led January 9, 1913.

T0 all whom it may concern Be it known that I, GEORGE FURUHOLMEN, asubject of the King of Norway residing at. Minneapolis, in the county ofllennepin and State of Minnesota, have invented cer tain new and usefulImprovements in Furnaces, of which the following is a specification.

My invention relates to improvements in furnaces, and has for its objectto provide a furnace havinnr an improved construction and arrangement offuel-feeding` and sus taining mechanism in combination with mea-ns fordirecting and controllingr the fuel gases and air so that a coltingeffect is had upon the fresh coal fed into the furnace and the fuelgases are mixed with the air at a point where the temperature of thefurnace is the highest, so that practically complete combustionimmediately takes place and a smokeless, or nearly smokeless eonibustionresults.

It is a further object of my invention to provide means for feeding thecoal from the rear to the front of the furnace chamber and to providemechanism for receiving the unconsumed material at the end of thefeeding mechanism and pushing said unconsunred material forward at thesame time that ashes and waste are permitted to drop through into the.ash pit.

lt is a further object of my invention to provide means for regulatingrthiI rate of feed of coal from the coal feeding chamber to the movinggrate and the thicknesst of the body of coal upon said grate. and alsoto provide means for reirulatiney the extent of grate surface suhieetedto draft` all for regulating and varying the intensity of the fire inthe furnace.

The. full objectsl and advantages of'my invention vcill appear inconnection n ith the detailed description ther iof and are particularlypointed out in the claims.

ln the drawings, illustrating the application of my invention in oneformrdfigurc 1 is a sectional lside elevation of a furnace embodying myimprovements. Fig. is a transverse section on line '2-2 of Fig. l. Fig.fi is a view similar to Fig. l illustrating;r a modified means offorcing the coal from the primary feeder ,to the grate. Fig. fl is nSpecification of Letters Patent.

Patented Mar. 23, 1915.

Serial No. 740.968.

longitudinal section of a part of a furnace showing my improvementsapplied to a different type of boiler. Fig. 5 is a. section on line.'5*-5 of Fig. 4. Fig. 6 is a sectional view across the front grate takenthrough the main receiving part of the grate and outside of one of themovable forwarding members. Fig. 7 is a similar sectional view taken inpart through one of the movable forwarding members. Fig. 8 is aSectional view through a portion of the grate along the grate shafttaken on line 8--8 of F ig. 6. Fig. 9 is a plan view of a portion of thereceiving grate. Fig. 10 is an enlarged sectional view of the front partof the receivY ing grate taken on line 10-10 of Fig. 6.

in the practice of my invention the pri maiv elements or featuresthereof are,- a feed chamber 11 located adjacent the rear part. of thefire box 12 opening thereinto through a passageway 13, a moving grate 14having the rear turn thereof adjacent the opening 13 and the uppersurface constantly moving toward the front of the furnace, a. coliingarch or baille 15 extending forwardly above the said moving grate toapoint above and a little short of the forward end of said grate, adamper plate 16 below the fuelreceiving portion of the grate forwithholdingr air from a part of the fuel on said grate, and acombination dumping and fuelforwarding grate mechanism 17 at the frontof said moving grate for receiving the unconsumed material from thegrate and sifting and forwarding the same. to the front of the furnaceor dumping, as desired.

ln the application of my invention shown in Figs. 1 and 3. the. feedchamber l1 may conveniently be located haelt of the wall 1S whichsupports the front. end of the boiler, while for the type of boilerAillustrated in Fig. 4 the chamber 11 may be formed at a suitable pointbeneath the boiler by a specially devised brick-work structure 1S). lneither event the coal or other fuel passes by gravity or is forcedthrough the opening 13 by automatic stolting mechanism upon the rear endof endless grate 14. At once upon passing to the grate 14 the coal issubjected to -heat and .vill begin to emit gases. lf, howeverVthesegases were allowed to escape directly into the combustion .mi and toiioiv thence toivould enter the corn-A a low temperature Where chamberitself was at a lov.Y tempcinture and a seriously :end otnuigviousl-vsmokeproducing Iumpiiou would result. l provide,

fi baille arch 1.7 extending forhin [he lire box 12 from above onpassage 13 to a point at con of the moving grate. .All from the fuelupon the grate w into the tire box 1i over the figc Q of the baille 15.This i cctlv above 'the hottest part of 1. the batiic arch l5 at itsfront edge vv; be heated red or White hot, so that the gas emittedfronrthc incoming fuel swap'. vto tbe fire box al: the hottest pointlirzco, biowmef'. if: -1i.. .wtwl to "l hem of the furnace from we ive.im below and will neceslei-conn- .rv bot. The gases from the lowiagalongthis bot surbig; lv heated before escap- .fz'iniicsccnt edge 20 ofthe ifi-ans ol tl e damper 16 air o pues: rbrougl. only the forfthegrate. so that. a large A the grate beneath the no ...ctefl to heat suchas i gases therefrom and t fue? before actual cour` place as the fuelreaches the i de. The air draft 'tgl'. the timivard portion of nim'intrato 1l. and through thc forwarding and dumping grate l. not only'provides the hottesty combustion of the fuel end of baliie arch 15, butalso the sa..

. 3 fuel -fl adm ,led smul pori lon 0 pari; of the but baille arch lf3is bfi-"vv 'the and tl of the bai e r; Where both and air are hosted toa very high temperature, Which insults in .web complete oxidation of thefuel gases that. the prodnrts of combustion are pract ally smokeless.

'Profi sentit or deer d: 'fr :it the to: Tl. a

.urtare exposed to 1 'ft of moving grate will hereinafter be described.sn the formV of niv device shown in Fig. 1.. which is a highiv usefuland satisfactmv feeding method. the rear por Aon of moving grateMextcnds beneath tite omini-gf 13 and the bottom of feed chan r 1l, sothat it iS noir Vf to lf: i the chamber ll .'ti'vla-eii n" in orde.-'hat the moving $9 grate `l tiniiallr sed forward the desired amount off'- o ver;y the thickfed upon moving of changing the .i provide avertical slidihc Ientire baille arch previouslv liberated diminish thethickness of the sheet of fuel fed forward by the'endless Fig. 3 amechanical Stoker pusher. type is shown for forcing the fuel from feedchamber 11 through passageway 13 and upon endless feeder 14. lWhen themechanical Stoker is used the endless feed grate 14 will not extend sofar rearwardly as in the form shown in Fig. 1, and a guido plate 28 willcarry the coal to the top of the endless feeder. Another forni ofmechanical distributing mechanism is shown in Figs. 4 and 5 in whichfuel is dis tributed from a side hopper 29 into the feed chamber 11, andfrom thence forced upon' the endless feed belt 14 by means of a spiralconveyor 30, preferably of diminishing diametrical dimensions as shown,in which case a guide plate 31 similar to the guide plate 28 may bearched around and above the spiral conveyor so as to direct the fuelforced upon said plate by the said spiral conveyer through thepassageway 13 and upon the moving grate 14. The mechanical stokers shownare referred to as typical of different mechanical operating devices forthe purpose. lVhen such devices are used the suppl) of fuel to themoving grate may be regulated by varying the rate of opera tion of the.mechanical Stoker.

It is to be noted that the modifications shown in Figs. 3 and 4 relateonl \7 to the means of supplying the'sheet of fuel to the movin grate.As shown in Fig. 3, a mechanical stokcr involving reciprocating pushersbelow hopper 11 is employed, which pushers force the fuel upon movinggrate 1-l. As shown in Fig. 4, the same result is obtained by an endlessscrew 30 which may project from a hopper 29 at one side of the furnace,as shown in Fig. 5. In either of these last mentioned forms the fuel ispositively forced upon the moving grate by the mechanical means shownwhich require a motor for operating the same; While in the form shown inFigs. l and'Q, the moving grate 14 extends below the mouth of hopper 11and the feed of the fuel to said grate is effected bygravitv.

The grate mechanism 1s supported upon a frame comprising side bars 32and end bars 33, said side bars having rollers 34 journaled thereon sothat if desired the frame may be dropped upon tracks 35 and grate 14. ln0H t of a common withdrawn from the furnace through an 'opening in thefront wall thereof provided for that purpose. Normally thc front end ofthe frame is sustained upon posts 36, and the rear end upon screwmembers 3T in a position sloping frpm the front to the rear,

the screw members 3T providing means forl adjusting the rear end of theframe. Upon a rear shaft 3S, journaled between side members 32, is asolid roller 39, and similarly journaled between side pieces 32 near thefront end thereof, is a shaft 40, preferably supplied with a series ofnarrow roller-ssl. The endless grate 14 consists of achain grate formedof transverse bars having draft openings through the same and extendingover roller 39 and the sets of rollers 41. Both shafts 3S and 40 may beprovided with worm wheels 4Q, with which mesh a pair of worms 43 upon ashaft 44 constantly driven from any desired source of power by which theroller 39 and rollers `rl1 are rotated at a uniform speed and theendless chain grate 24 continuously and automatically moved from therear toward the front of the fire box.

The damper 16 comprises a ined plate 45 supported upon cleats on sidepieces 32 and a crossbar 4G adjacent roller 39, said plate 45 hap-fingthe end if thereof in close proximity to the periphery of roller .-lflso as to close dra ft communication from below damper plate, 15 throughthe grate 14. Secured to crossbar 476 and another crossbar 4S toward'theforward portion of grate bar 14, are longitudinal bars 49 upon whichslide a movable, damper plate 50, said plate being provided on the underside thereof with racks 5t, which are engaged by pinions 52 on a shaftjournaled in side pieces 32, said shaft 53 extending vbeyond side/piece3Q between worm wheels 42 on shafts 38 and 40, and having on theextended end thereof a hand wheel By turning the hand provided withcircular apertures 64, through which extends loosely a squared, ,hollowshaft (i5 having the corners round-:d so that the same may rotate in thesaid apertures C4. The upper front portions of ribs 61 are formed asindicated at G6 so as to engage the fixed grate member and preventtheforward portion of plate 59 from Contact ing with the curved portion ofmoving chain grate l section 5S and the fixed section are conjointlyformed so as to provide a hollow or depressed portion, 6T, extendingrearwardly in a curved ascending plane into close proxunity with thedescending portion of mov-4 ing grate 14. Back of apron 59 and betweenrilis 61 are positioned a series of grate bars fast on shaft 65 andmovable in unison by such shaft. It is noted that the grate bars 68 areformed with a. curved wheel 54 the movable damper member() will he slidbackward 0r forward relative to baffle arch 15, opening more or less ofthe fuel supporting portion of lmoving grate 1t to draft of air .frombeneath.

The front receiving and forwarding grate l? comprises a stationaryportion 55 held in fixed position at the front of the furnace. saidportion .fi-3' being formed 'with draft openings 56 and 5T'. Between thefixed grate portion 55 and the peripheral curve of moving grate 14,wherel thev same goes over rollers 41. is located a grate section 58.said section comprising a front apron 59 formed with a series of draftopenings (if) therein Vand a series of depending ribs 61, crossbars orwebs G2 at the rear of said ribs, and a crosshar (i3 at the frontthereof operating to bind the same rigidly together at the lower portionthereof. The ribs 61 are upper surface corresponding to that of the ribsG1, and also each of said grate bars is provided with transverse draftapertures (S9 and longitudinal draft apertures 70, formed between pairsof forwardly extended ribs 71 which come' into proximity to projectingportions of fixed grate 55 and are adapted to engage and crush c linkersor other obstructions which may get on to the grate bars 68. The rearportion of the grate bars v(it is formed as an extended arcuate flange72, as bcstshown in Figs. G and 7. Maferial upon the grate and withinthe depressed portion (37 will be pushed in a forward direction when thegrate sections (3S. are rocked upwardly'; and material upon the apron 59will be restrained from falling through between ribs 61 by aforesaidfianges 72.

From the above it will be seen thatthe grate bars GS are secured 'tomove together lupon and with the shaft 65. On one of said grate bars isformed a forwardly projecting crank arm 73, to the farther end of whichis connected an operating link or har 74 which projects through thefront of the furnace and is pivotally connected to Yan operating lever75. By this means t-he'shaft 65 may be rocked in a direction to causethe grate bars G8 to rise between the adjacent ribs 61, the operativeportions 76 of said bars moving upwardly and forwardly so as to push thema* rial resting above thehollow portion (i7 of the grate toward thefront ofthe fire box, the loose ashes and clinkers droppingthrough'between the rear Aportions of ribs (51. Clinkers that are toolarge to pass between said ribs G1 will be engaged between the ends ofribs 71 and portions of the fixed grate 55, and by operative portions76, said clinkers thereby being broken so that they will fall through.One of the .depending ribs G1 is provided with an integral downwardlyand forwardly projecting crank arm Itis to he noted that the grate' the.baille arch.

77 jivhich is positioned adjacent the crank arm 73. To the lower end ofcrank arm 77 is connected an operating har or lifnl. which projectsforwardly through the front side of the furnace and is pivotallyconnected to an operating` lever, 79. By operating the lever 79 thegrate plate 5S may be swung upvvardly and forwardlyg dumping thecontents thereon into the. ash pit. Preferably in accomplishing thedmnpinpr action the grate and the grate hars G8 will be operatedsimultaneously through levers '73 and 77.

The grate section 58 and the sha1-ier bars (3S taken togetherconstitutenot only means for shaking or dumping the ashes, but a truegrate havingr a multiplicity of draft spaces for providing complete andeffectual drafttothe material loeat-ediipon this grate. The fixed gratesection '55 also provides ample draft spaces. The purpose of thisarrangement, therefore, is to provide a proper grate surface forreceiving and retaining unconsumed material from the moving grate l-l;and supplying the requisite drafts of air to ellect proper combustion ofsuc-h material7 as well as shaking and dumping mechanism. lfloreover,the shaking device has a peculiar land novel function, namely-to movethe material on the grate from the rear thereof toward the front so thatthe most fully consumed fuel and ashes will be contiiunzlly pushed tothe frontof the grate adjacent the furnace opening and farthest from theboiler, Where, for convenience of operation and from the standpoint ofpractical economy, it is desirable to have a relatively loivtemperature.

It is to be noted that my entire organization provides a fueldistributing and draft mechanism not only efficient in a high degree forproducing practically smokeless combustion, but also of unusualconvenience tothe fireman or operator, who always Will-have a clear viewof the fire hed and has convenient and ready access to all operatingparts of my device. It is also true that the arrangement of movinggrate, fuel supply, hopper or box admission, passage-way to the movinggrate and balle arch above the .moving grate are assembled in a relativeposition such as to give the best possible results.

The baille arch must be spaced sufficient distance above the coal uponthe moving gratefto permit ready movement of gases freed from said' coaltoward the end 20 of Preferably also. as shown, the baille arch shouldbe inclined upwardly. This baille arch Will not prove effective for thepurpose if made .too long, and for this reason it is impracticable touse a baille arch and a movingr grate vvhere said arch and grate extendto the lrcar'iend of a. boiler of any considerable length. The draftcontrolling apparat-11s below the moving grate'is absolutely essentialto draft regulation "o that the hot part of the fire `will be. at theforiva rd end of the moving grate and he'low the end 20 of the baillearch. lf a. thin sheet of (foal is to be fed for keeping a comparativelylon' fire, and no damper mechanism avere provided. the lire would creepback beneath the baille arch to the. coal admission point, and evenmight finally reach the fuel in the supply hopper'. The same result,vonld follow to a degree if a tliicln-,r .sheet oi" fuel were fed. Acombustion onthe moving grate beneath the. baille arch at a point muchto the rear of the end 20 thereof is not desirable, since it, voulil hewasteful and he liable to canse smoking.

l claim: i

l. A. furnace comprising a tire box and a grate therein continuouslymovingr from the rear to a point near the front of the fire box, meansforcontinuously delivering fuel upon the rear 5nd of said moving grate,means above the grate for causing the gases liberated from the fuel tobe delivered into the eomluistion chamber near the forward end of thegrate, means hel-ow the grate for limiting the delivery of air throughthe g ate to a point approximately below the point of delivery of saidand a. 'normally stationary grate at the front of and Within the firebox positioned to receive and hold material from the moving grate forfurther combustion at a point which is close to the hottest, portions ofsaid combustion chamber.

2. A furnace comprising a fire box and a grate therein continuouslymoving from the rear to a point near the front of the. lire box, meansfor continuously delivering fuel uponv the rear end of said moving,rgrate, ay bafllc arch above said moving grate extending forwardly sothat the gases released from the fuel on the `frate will be deliveredinto the combustion chamber at a Ipoint approximately above the .forwardend of the moving gratea draft plate below the moving,

grate for limitingair draft through the front portion only of the sameto produce the hottest combustion area. in the fire lion at the front ofthe moving grate and belofvi7 the end of said baille arch, and anormallystationary grate at the front of and Within.

the firebox positioned to receive and Ahold. i material from themoving.; grate for further y combustion at a point which is close to thehattest portions of said combustion chamber. l i

3. A fiirnaee comprisingr rear to the front of the tire-box and comafire-box,a solid roller outside of the rear of said tire-box, av

prising a (lished surface, said receiving grate including movable grattebars for engaging und fox'waldingfuel on the receiving grate, Saidmovable bars having arcuate flanged rear portions to prevent materialfalling through the receiving grate al', the rear part thereof when saidbars are operated.

